/* Workshop: walnut header plank, plywood ground, each calculator on a clipboard with a graph-paper cut list.
   Self-hosted slab face for headings (lumber-stamp feel), system font for body. No third-party requests. */
@font-face { font-family: "Zilla Slab"; font-weight: 600; font-display: swap; src: url(fonts/zilla-slab-600.woff2) format("woff2"); }
@font-face { font-family: "Zilla Slab"; font-weight: 700; font-display: swap; src: url(fonts/zilla-slab-700.woff2) format("woff2"); }

:root {
  --ply: #eadbc0;        /* birch plywood ground */
  --paper: #fffaf0;      /* clipboard paper */
  --ink: #2b1d12;        /* walnut-dark text */
  --muted: #6f5a44;
  --line: #d9c4a0;
  --pine: #d4a26a;       /* light lumber */
  --oak: #a8713f;        /* clipboard edge, borders */
  --walnut: #4a2f1b;     /* header plank */
  --walnut-ink: #f6ead6;
  --tape: #f2b705;       /* tape measure */
  --tape-ink: #2b1d12;
  --grid: rgba(70, 120, 170, .13);
  --ok: #3b7a3e; --warn: #b8470f;
  --display: "Zilla Slab", Rockwell, "Roboto Slab", Georgia, serif;
  --body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --grain: repeating-linear-gradient(179.4deg, rgba(90, 55, 20, .035) 0 1px, transparent 1px 5px, rgba(90, 55, 20, .02) 5px 6px, transparent 6px 13px),
           repeating-linear-gradient(180.6deg, rgba(90, 55, 20, .05) 0 2px, transparent 2px 23px, rgba(90, 55, 20, .03) 23px 26px, transparent 26px 41px),
           repeating-linear-gradient(179deg, rgba(255, 255, 255, .07) 0 1px, transparent 1px 37px);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) { :root {
  --ply: #241910; --paper: #2f2218; --ink: #f1e4cf; --muted: #c0a888; --line: #4c3725;
  --pine: #b9864f; --oak: #8a5a30; --walnut: #160e08; --walnut-ink: #f1e4cf;
  --tape: #f2b705; --tape-ink: #1d140c; --grid: rgba(150, 190, 230, .07);
  --ok: #7cc47f; --warn: #f08a4b;
  --grain: repeating-linear-gradient(180deg, rgba(0, 0, 0, .18) 0 1px, transparent 1px 7px),
           repeating-linear-gradient(180deg, rgba(255, 220, 170, .025) 0 2px, transparent 2px 19px);
  color-scheme: dark } }

* { box-sizing: border-box; }
body { margin: 0; background: var(--ply); background-image: var(--grain); color: var(--ink); font: 17px/1.6 var(--body); padding-inline: 16px; }
.wrap { max-width: 1040px; margin: 0 auto; padding-block: 0 48px; }
a { color: inherit; text-underline-offset: 3px; text-decoration-color: var(--oak); }
a:hover { color: var(--warn); }

/* header: one walnut plank, full width */
.top { margin-inline: -16px; padding-inline: 16px; background: var(--walnut); background-image: var(--grain); color: var(--walnut-ink);
       border-bottom: 4px solid var(--tape); }
.bar { max-width: 1040px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; gap: 12px 20px; flex-wrap: wrap; padding-block: 14px; }
.logo { font: 700 24px/1 var(--display); letter-spacing: .01em; text-decoration: none; display: inline-flex; align-items: center; gap: 10px; }
.logo:hover { color: var(--tape); }
.top nav { display: flex; gap: 18px; flex-wrap: wrap; align-items: center; font-size: 15px; }
.top nav a { text-decoration-color: var(--tape); }
.top nav a:hover { color: var(--tape); }
.units { display: inline-flex; border: 1px solid rgba(246, 234, 214, .35); border-radius: 4px; overflow: hidden; }
.units button { font: 600 13px var(--mono); padding: 5px 10px; border: 0; background: transparent; color: var(--walnut-ink); cursor: pointer; }
.units button[aria-pressed="true"] { background: var(--tape); color: var(--tape-ink); }
.met { display: none; }
.metric .imp { display: none; }
.metric .met { display: inline; }

h1, h2, h3 { font-family: var(--display); font-weight: 700; text-wrap: balance; }
h1 { font-size: clamp(34px, 5.5vw, 50px); line-height: 1.05; margin: 30px 0 8px; }
h2 { font-size: 28px; line-height: 1.15; margin: 40px 0 8px; }
.lede { color: var(--muted); max-width: 62ch; margin: 0 0 30px; }

/* the calculator: a clipboard (oak edge) holding paper */
.calc { position: relative; background: var(--paper); border: 10px solid var(--oak); border-radius: 10px;
        box-shadow: 0 2px 0 rgba(0,0,0,.08), 0 14px 30px -18px rgba(60, 35, 10, .45);
        padding: 30px 24px 24px; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); gap: 32px; }
.calc::before { content: ""; position: absolute; top: -20px; left: 50%; translate: -50% 0; width: 120px; height: 26px; border-radius: 6px 6px 3px 3px;
        background: linear-gradient(#d5d9dc, #8f969b); box-shadow: inset 0 -3px 0 rgba(0,0,0,.2); } /* clip */
@media (max-width: 720px) { .calc { grid-template-columns: minmax(0, 1fr); padding: 28px 14px 16px; border-width: 8px; } }
.fields { display: grid; gap: 14px; align-content: start; }
.row2 { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 12px; }
label { display: grid; gap: 4px; min-width: 0; font-weight: 600; font-size: 15px; }
.in { display: flex; border: 1.5px solid var(--line); border-radius: 4px; background: var(--paper); }
.in:focus-within { border-color: var(--oak); outline: 2px solid var(--tape); outline-offset: 1px; }
.in input, .in select { flex: 1; width: 100%; min-width: 0; border: 0; background: transparent; color: var(--ink); font: 500 17px var(--mono); padding: 8px 10px; }
.in input:focus, .in select:focus { outline: none; }
.in span { padding: 8px 10px; color: var(--muted); font: 500 14px var(--mono); border-left: 1.5px solid var(--line); white-space: nowrap; background: rgba(168, 113, 63, .08); }
.hint { font-weight: 400; color: var(--muted); font-size: 13px; }

/* results: graph-paper cut list */
.results { display: grid; gap: 16px; align-content: start; min-width: 0; padding: 18px; border-radius: 4px; border: 1px solid var(--line);
           background-color: var(--paper); background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px);
           background-size: 16px 16px; }
.big .v { font: 700 52px/1 var(--display); font-variant-numeric: tabular-nums; }
.big .u { color: var(--muted); font-size: 15px; margin-top: 2px; }
.big::after { content: ""; display: block; height: 14px; margin-top: 10px; border-radius: 2px; /* tape measure blade */
  background: repeating-linear-gradient(90deg, var(--tape-ink) 0 1.5px, transparent 1.5px 32px) bottom / 100% 9px no-repeat,
              repeating-linear-gradient(90deg, var(--tape-ink) 0 1px, transparent 1px 8px) bottom / 100% 5px no-repeat,
              var(--tape); }
.out { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; font-size: 16px; }
.out td { padding: 7px 0; border-bottom: 1px dashed var(--line); vertical-align: top; }
.out td:last-child { text-align: right; font: 600 15px var(--mono); padding-left: 12px; }
.checks { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; font-size: 14px; }
.checks li { padding: 6px 10px; border-radius: 4px; background: var(--paper); border: 1px solid var(--line); }
.checks .ok::before { content: "✓ "; color: var(--ok); font-weight: 700; }
.checks .warn { border-color: var(--warn); }
.checks .warn::before { content: "! "; color: var(--warn); font-weight: 700; }
.diagram svg { width: 100%; height: auto; display: block; }
.diagram text { fill: var(--muted); font: 600 12px var(--mono); }
.diagram .fill { fill: var(--pine); stroke: var(--walnut); stroke-width: 1.5; }
.diagram .ln { stroke: var(--walnut); stroke-width: 1.5; fill: none; }
.diagram .thin { stroke: var(--oak); stroke-width: 1; fill: none; }
.diagram .dim { stroke: var(--warn); stroke-width: 1; stroke-dasharray: 5 4; fill: none; }
.diagram .soil { fill: var(--oak); fill-opacity: .3; }
@media (prefers-color-scheme: dark) { .diagram .fill, .diagram .ln { stroke: var(--ink); } }

article { max-width: 68ch; }
code { font: 500 14px var(--mono); background: var(--paper); border: 1px solid var(--line); padding: 2px 6px; border-radius: 3px; overflow-wrap: anywhere; }
.tbl { overflow-x: auto; background: var(--paper); border: 1px solid var(--line); border-radius: 4px; padding: 4px 14px; }
.tbl table { border-collapse: collapse; min-width: 100%; font-size: 16px; }
.tbl td, .tbl th { padding: 8px 12px 8px 0; border-bottom: 1px dashed var(--line); text-align: left; }
.tbl tr:last-child td { border-bottom: 0; }
.tbl th { font: 700 14px var(--display); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
details { border-bottom: 1px dashed var(--oak); padding: 10px 0; }
summary { font-weight: 600; cursor: pointer; }
summary::marker { color: var(--oak); }

/* related links: a pine shelf */
.related { margin-top: 44px; padding: 18px 22px; border-radius: 6px; background-color: var(--pine); background-image: var(--grain); color: #2b1d12;
           box-shadow: inset 0 -4px 0 rgba(0,0,0,.12); }
.related h2 { margin: 0 0 8px; font-size: 20px; }
.related ul { margin: 0; padding-left: 18px; columns: 2 220px; }
.related a { text-decoration-color: rgba(43, 29, 18, .5); }
.related a:hover { color: #6b1f00; }

/* home: each calculator is a board */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr)); gap: 14px; margin-top: 8px; }
.card { display: grid; gap: 4px; align-content: start; padding: 18px 20px 20px; border-radius: 5px; text-decoration: none; color: #2b1d12;
        background-color: var(--pine); background-image: var(--grain); box-shadow: inset 0 -4px 0 rgba(0,0,0,.13), 0 6px 14px -10px rgba(60,35,10,.6);
        transition: translate .15s; }
.card:nth-child(3n+2) { background-color: #dcae76; }
.card:nth-child(3n) { background-color: #c99358; }
.card:hover { translate: 0 -2px; color: #2b1d12; }
.card b { font: 700 21px/1.2 var(--display); }
.card span { font-size: 15px; color: #4a3422; }

footer { margin-top: 56px; padding-top: 16px; border-top: 2px solid var(--oak); font-size: 14px; color: var(--muted); display: flex; gap: 8px 18px; flex-wrap: wrap; }
:focus-visible { outline: 2px solid var(--tape); outline-offset: 2px; }
@media (prefers-reduced-motion: reduce) { .card { transition: none; } }